Jump out of IC method Battery management system innovation -Lithium - Ion Battery Equipment
Objectively speaking, the IC dedicated to battery management has made achievements in the early bMS industry and led the development of bMS products. It is precisely because of the special chips that the design of bMS can be greatly simplified, and the miniaturization and reliability of products can be greatly improved. But at the same time, we should also see the limitations of the special chips. As mentioned earlier, battery management dedicated chips have also been developed with the use of lithium ion batteries. In the early days, lithium ion batteries were mostly used in small electronic devices, and later were widely used in laptops. Until now, battery management dedicated chips have always been used for low serial number and small devices.
When the lithium-ion battery pack was used in electric vehicles, the situation began to change. The lithium-ion battery pack for electric vehicles is used in series with high number of strings and large capacity batteries. The number of dozens or even hundreds of strings is no longer comparable to the serial use of several strings of this single digit level in laptops. Special ICs are not idle, and they quickly launched products with more strings. However, considering the voltage and use complexity, they generally do not exceed 20 strings. The typical architecture of bMS designed with these ICs is the aggregation architecture. There are only connections between the bMS and the battery pack. The number of connections depends on the number of battery pack strings. The number of battery management dedicated chips on the bMS circuit board also depends on the number of battery pack strings.
It can be seen from the diagram that the advantages of clustered bMS products are simple structure and low cost. When the number of battery pack strings is low, such as 10 strings, the connection is not too complicated. In addition, when the capacity of the battery pack is small, the bMS installation position can be close to the entire battery pack to shorten the connection distance. The battery pack - bMS, the entire energy system is relatively compact and integrated, which is more suitable for electric scooters and electric scooters. However, when used on the lithium-ion battery pack of electric vehicles, due to the large battery capacity, the physical size after grouping is relatively large, and the connection will be long and vary in length. In addition, the number of strings will be large, and the arrangement of dozens or even hundreds of lines will be very troublesome.
Another important detail is that the order of these connections should be fixed. Because the pins of the special chip have already defined the battery series connection order in advance, the connections on each string of batteries should be connected to the connector pins designated by the bMS. Although there is no difficulty in bMS design, it is a big trouble in the actual connection between bMS and battery pack. Generally, one end of the wire is connected to the battery, and the other end is connected to the bMS through a plug-in. The work of connecting to the battery is currently done manually, and it will be difficult to be done by machines in the future. The wire connected to each battery string and each electrode can not make any mistakes. It is conceivable that the whole work amount. Through the decomposition of the aggregation architecture, we can see that dedicated ICs are more suitable for small capacity and low number of strings. In large capacity and high number of strings, there will be a disadvantage of complex connections and one-to-one correspondence.